Regional anesthesia (RA) is a powerful technique to reduce both perioperative and chronic pain. RA can provide significant benefits to patients since it requires only light sedation to accompany the regional blockade and thereby results in a low incidence of postoperative complications. In spite of its advantages, only 5-20% of patients eligible for RA receives this technique. Patient selection for RA depends primarily on a practitioner's confidence in applying the method. The proposed Phase 1 research is meant to develop a device, which will improve physician confidence by providing real-time feedback during RA. The success of the block depends on locating the deeply placed nerves for peripheral nerve blockade or the neurovascular bundle for plexus blockade. while avoiding surrounding vital structures. Since target nerves lie in close proximity to major blood vessels, guidance will be provided using a combination of Doppler ultrasound (for long-range direction) and electrical nerve stimulation for confirmation of needle placement. As part of this Phase I study, preliminary designs for ultrasound transducers, electrode patterns, materials, and construction methods will be identified. Successful completion of Phase I will lead to prototype development and testing during the Phase II portion of the project. PROPOSED COMMERCIAL APPLICATIONS: RA potentially benefits both patients and payers since its use promotes rapid recovery, shortened hospital stays and excellent pain control. The overall cost of RA is about 1/3 of costs associated with general anesthesia. The development of a disposable device for guiding RA will result in a commercially viable product, which will increase the use of RA and decrease the costs associated with surgical anesthesia and post-operative care.